<!DOCTYPE html>
<html lang="en" xmlns:v-on="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
<div id="app">
    <h2 v-if="isShow">生日:
        {{new Date(birthday).getFullYear()}}-
        {{new Date(birthday).getMonth()}}-
        {{new Date(birthday).getDay()}}
    </h2>
</div>
<script type="text/javascript">
    var app = new Vue({
        el: "#app",
        data: {
            birthday: 1616566607104
        },
        computedOffset: {
            birth() {
                const day = new Date(this.birthday);
                return day.getFullYear() + "-" + day.getMonth() + "-" + day.getDay();
            }
        }
    });
</script>
</body>
</html>